Product Overview

The Hayward Perflex 20 sq ft Modular Filter with Clamp W3EC40AC is an extended-cycle DE filter designed to deliver clear, sparkling pool water with simple, efficient operation. Built with Hayward’s patented Flex-Tube design, this filter uses diatomaceous earth to capture fine particles and help maintain excellent water clarity.

Unlike traditional backwash DE filters, the Perflex system does not require backwashing. Instead, the exclusive bump handle activates the Flex-Tubes, helping remove dirt and DE powder from the tube surfaces so fresh filtering surfaces can form. This helps extend filter cycles, reduce water waste, and simplify maintenance.

The W3EC40AC includes an easy-access clamp assembly, making service access more convenient compared with older bolt-style designs. Hayward lists this model with 20 sq. ft. effective filtration area, 40 GPM design flow rate, 4 lb DE capacity, and 26.5" x 16" x 16" product dimensions.

Ideal For

Above-ground swimming pools
Compatible in-ground pool applications
Pool owners looking for DE filtration without backwashing
Replacement for Hayward EC40AC / W3EC40AC filter systems
Customers wanting fine-particle water clarity
Systems requiring a compact 20 sq. ft. DE filter
Pool owners who prefer clamp-style service access

Key Features

20 sq. ft. DE Filtration Area

The 20 square foot effective filtration area provides dependable dirt and debris capture for residential pool systems.

Patented Flex-Tube Design

Hayward’s Flex-Tube system works with DE powder to create fresh filtering surfaces during the cleaning cycle, supporting clear water and extended filter operation.

No Backwashing Required

The Perflex extended-cycle design provides DE filtration without traditional backwashing, helping conserve water and simplify pool maintenance.

Easy-Access Clamp Assembly

The clamp design provides easier access to the internal filter components for cleaning and service.

Exclusive Bump Handle

The integrated bump handle activates the Flex-Tubes, helping purge dirt and used DE powder from the tube surfaces so the filter can continue operating efficiently.

Superior DE Water Clarity

Diatomaceous earth filtration helps remove fine particles from pool water for a clean, polished appearance.

Self-Venting Design

The filter is designed to expel air through the filtered water returning to the pool.

Uniform DE Coating

The combination diffuser and lower mixing chamber help produce an even coating of DE on the Flex-Tubes for consistent filtration performance.

Compact Modular Design

The compact 16" x 16" footprint makes this filter a practical option for many above-ground pool equipment areas.

Benefits

The Hayward W3EC40AC is a strong choice for pool owners who want the clarity of DE filtration with easier maintenance than traditional backwash systems. Its extended-cycle operation helps reduce water waste, while the bump handle makes routine cleaning simple without opening the filter every time.

With its 20 sq. ft. filtration area, 4 lb DE charge, 40 GPM design flow rate, and easy-access clamp assembly, this model is a practical solution for residential pool systems when properly matched with the pump, plumbing, and pool size.

Specifications

What’s Included

Hayward W3EC40AC Perflex 20 sq. ft. DE filter
Flex-Tube filter assembly
Bump handle mechanism
Easy-access clamp assembly
Filter tank and base assembly
Internal diffuser / lower mixing chamber components

Pool-grade DE powder is not included.
Pressure gauge is listed by Hayward as not included for this model.
Pump, hoses, fittings, and plumbing accessories are not included unless supplied separately by the seller.

Customer-Facing Q&A

Is this a cartridge filter?

No. The Hayward W3EC40AC is a DE filter, not a cartridge filter. It uses diatomaceous earth powder with Hayward’s Flex-Tube filtration system.

Does this filter require backwashing?

No. The Perflex W3EC40AC is designed for no-backwash operation. The bump handle helps clean the Flex-Tubes and redistribute the DE powder.

How much DE powder does this filter need?

This filter requires 4 lbs. of pool-grade diatomaceous earth.

Is DE powder included?

No. DE powder must be purchased separately.

What is the flow rate?

The Hayward W3EC40AC is listed with a 40 GPM design flow rate.

Does this model include a clamp?

Yes. This version is the 20 sq. ft. Perflex model with clamp and includes an easy-access clamp assembly.

Does this filter include a pressure gauge?

Hayward lists the W3EC40AC as pressure gauge not included.

What type of pool is this filter for?

Hayward lists this model for above-ground and in-ground pool applications when properly matched with the pump, plumbing, and pool requirements.

What does the bump handle do?

The bump handle activates the Flex-Tubes, helping remove dirt and DE powder from the tube surfaces so fresh filtering surfaces can form.

What makes Perflex different from standard DE filters?

Perflex filters use Hayward’s patented Flex-Tube system and bump handle cleaning method, allowing extended filter cycles without traditional backwashing.